1. Field of the Invention
The invention relates to a process for the preparation of .beta.-resorcylic acid derivatives and the use of certain .beta.-resorcylic acid derivatives as a fragrance or in perfumes.
2. The Prior Art
Processes for the preparation of .beta.-resorcylic acid derivatives are already known. U.S. Pat. No. 3,944,596, granted to Cohen, describes a process for the preparation of resorcylic acid mono- and dialkylesters in which the corresponding dihydroresorcyclic acid esters are reacted with N-halogenoamides as aromatizing agents. A similar process is disclosed in U.S. Pat. No. 4,142,053, granted to Klein, according to which the dihydro-.beta.-resorcylic acid esters are aromatized by heating with acetic anhydride/sulfuric acid to form diacetates, and these diacetates are hydrolyzed under alkaline or acid conditions in an additional reaction stage. These processes have the disadvantage that the accessibility of the starting substances is relatively difficult and, as a rule, additional synthesis steps are required.
.beta.-Resorcylic acid esters can, furthermore, be prepared in accordance with U.S. Pat. No. 4,420,629, granted to Schmidt, by reaction of .alpha.-pyronyl-6-acetic acid esters with a base, the .alpha.-pyronyl-acetic acid esters being prepared in accordance with German Patent No. 2,916,648. This process has the disadvantage that it likewise comprises several stages and starts from educts which are not readily accessible.
A process for the preparation of .beta.-resorcylic acid-6-alkyl esters by reaction of diketene (4-methylene-2-oxetanone) with .beta.-ketocarboxylic acid esters and sodium hydride in a molar ratio of 1:1:1 is furthermore known from a publication by Tetsuzo Kato and Toyaharu Hozumi in Chem. Pharm. Bull. 20, 7 (1972) 1574-8. This process leads to only low yields and also has the disadvantage that the sodium hydride used as the catalyst is difficult to handle.